The Ultimate CSS Gradient Generator describes itself as "A powerful Photoshop-like CSS gradient editor", and delivers on that promise.
Using familiar swatches, a great color picker and some nice presets, this really is the ultimate tool for generating CSS3 gradients. Just create your gradient like you would in Photoshop, and copy the generated code on the right.
On the creative side, the tool supports both linear and radial gradients, handy hue/saturation adjustments (but does not support multiple backgrounds). When generating the code, users can pick their preferred color format , toggle multi-stop support for IE9 via SVG and even choose to output the code in SCSS, to use with SASS & Compass.
To top all these, the generator boasts two killer features - Import from CSS, which gets any syntax of gradient and outputs the rest, and 'import from image', which is a huge help when all you have is an image of a gradient and identifying color-stops by hand doesn't sound like fun to you.
The generator has some more neat features like a live preview, gradient permalinks and so on, so check it out for yourself, and enjoy creating awesome gradients for the web.